Volatile organic compounds produced in milk by Enterococcus faecalis.

Enterococci can contribute positively to the development of flavour during cheese ripening as their presence is consistently reported in many raw milk cheeses. They can influence flavour taste and texture of cheeses as they produce several enzymes that interact with milk components, thus promoting important biochemical transformations. For this survey, 40 Enterococcus faecalis strains, collected in different valleys in northwest Italy, were inoculated in milk and submitted to head-space solid-phase-micro- extraction gas chromatographymass spectrometry analysis. The major volatile compounds detected were: ethanol, diacetyl, acetoin, acetic and benzoic acids. The variability was huge, demonstrating a very different enzymatic activity among strains. Apart from other important phenological parameters for characterizing strains that can be used as starter cultures, it seems useful to also give some information about their capability of enhancing flavour characteristics in the cheese.